Non-contact temperature detection device and motor
By designing a non-contact temperature detection device with sensing and detection units in the motor, the problems of large environmental impact and high cost are solved, achieving low-cost and accurate temperature measurement, which is suitable for non-contact temperature detection of motors.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- GUANGDONG GOBAO INTELLIGENT TECHNOLOGY CO LTD
- Filing Date
- 2025-08-12
- Publication Date
- 2026-07-24
AI Technical Summary
Existing non-contact temperature detection devices are greatly affected by the environment in motors and are costly, especially when gears are coated with lubricating grease, resulting in inaccurate measurements.
Design a non-contact temperature detection device, including a sensing unit and a detection unit. The first circuit of the sensing unit is in contact with the object to be measured, and its equivalent impedance changes with temperature. The second circuit is coupled to the first circuit, and the temperature is calculated by detecting the peak voltage.
It achieves low-cost, non-contact temperature measurement without environmental constraints, avoids the influence of lubricating grease, has a simple structure, and is widely applicable.
Smart Images
Figure CN224552567U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of temperature measurement technology, and in particular to a non-contact temperature detection device and a motor. Background Technology
[0002] In electric motors, the lifespan of gears in the transmission system is closely related to gear temperature. Therefore, monitoring gear temperature is extremely important to ensure the reliability of gears in application.
[0003] Since the gears of a motor rotate at high speed during operation, direct contact for temperature measurement is not feasible. Common non-contact temperature measurement methods mainly involve pointing an infrared probe at the surface of the object being measured. Utilizing the positive correlation between the radiation intensity detected by the infrared probe and temperature (Steffen-Boltzmann law), the signal conversion circuit integrated within the infrared probe converts the detected radiation intensity into an electrical signal, which is then processed by subsequent circuitry to calculate the actual temperature value.
[0004] However, infrared detectors are usually expensive, and their reception of infrared radiation is greatly affected by the environment. In addition, gears are coated with lubricating grease, and parameters such as the thickness and transparency of the lubricating grease can affect the measurement of the infrared detector. Even worse, when the gears are running, the grease may be flung onto the infrared detector, completely blocking it and rendering the infrared detector unusable. Utility Model Content
[0005] This invention provides a non-contact temperature detection device and a motor, which can realize non-contact temperature measurement of the object under test without environmental constraints. Furthermore, the device has a simple structure and saves production costs.
[0006] According to one aspect of the present invention, a non-contact temperature detection device is provided, comprising: a sensing unit and a detection unit; wherein, the sensing unit includes a first circuit and a second circuit; the first circuit is disposed inside or on the surface of the object to be measured, and the equivalent impedance of the first circuit changes with the temperature of the object to be measured; the second circuit is coupled to the first circuit, and the equivalent impedance of the second circuit changes with the equivalent impedance of the first circuit; the detection unit is electrically connected to the second circuit and is used to detect a peak voltage and calculate the equivalent impedance of the second circuit based on the peak voltage, so as to determine the temperature of the object to be measured based on the equivalent impedance of the second circuit.
[0007] Optionally, the first circuit includes a thermistor, a first capacitor, and a first electromagnetic coil connected in parallel; the thermistor is in direct contact with the object under test; and the first capacitor and the first electromagnetic coil are in a parallel resonant state.
[0008] Optionally, the second circuit includes a second electromagnetic coil, a second capacitor, a third capacitor, an inductor, and an inverter; wherein the second electromagnetic coil and the second capacitor are connected in series and then connected in parallel with the third capacitor and the inductor, and the inverter is connected in series with the inductor; the inverter is used to convert external DC signals into AC carrier signals; the second electromagnetic coil is coupled to the first electromagnetic coil; the second electromagnetic coil and the second capacitor are in a series resonant state, and the third capacitor and the inductor are in a parallel resonant state.
[0009] Optionally, the carrier frequency of the AC carrier signal is f; the resonant frequencies of the first capacitor and the first electromagnetic coil, the second electromagnetic coil and the second capacitor, and the third capacitor and the inductor are all f.
[0010] Optional, peak voltage V dect The equivalent impedance Z of the second circuit ref Satisfying the following relationship: V dect =I*Z ref The equivalent impedance Z of the second circuit ref The equivalent impedance R1 of the first circuit satisfies the following relationship: Z ref =(2πf*M) 2 / R1; where I=U / (2πf*L3), U is the maximum voltage of the AC carrier signal, L3 is the inductance value of the inductor; M is the mutual inductance value of the first electromagnetic coil and the second electromagnetic coil.
[0011] Optionally, the mutual inductance M of the first electromagnetic coil and the second electromagnetic coil is determined based on the relative position of the first electromagnetic coil and the second electromagnetic coil, the geometric parameters of the first electromagnetic coil and the second electromagnetic coil, and the permeability of the surrounding medium.
[0012] Optionally, the detection unit includes an envelope detection circuit.
[0013] Optionally, the envelope detection circuit can be any of the following: diode envelope detection circuit, precision rectifier envelope detection circuit, peak envelope detection circuit, or logarithmic amplifier envelope detection circuit.
[0014] According to another aspect of the present invention, an electric motor is provided, including the non-contact temperature detection device of any of the above embodiments.
[0015] Optionally, the object to be tested is the rotor of a motor, and the second circuit and detection unit of the non-contact temperature detection device are located on the stator side of the motor.
[0016] The technical solution of this utility model embodiment involves designing the structure of a non-contact temperature detection device, which includes a sensing unit and a detection unit. The sensing unit includes a first circuit and a second circuit. The first circuit is disposed inside or on the surface of the object to be measured, and its equivalent impedance changes with the temperature of the object. The second circuit is coupled to the first circuit, and its equivalent impedance changes with the equivalent impedance of the first circuit. The detection unit is electrically connected to the second circuit and is used to detect peak voltage and calculate the equivalent impedance of the second circuit based on the peak voltage, thereby determining the temperature of the object to be measured based on the equivalent impedance of the second circuit. On one hand, because the second circuit is coupled to the first circuit and the detection unit is electrically connected to the second circuit, only the first circuit needs to be disposed inside or on the surface of the object to be measured; neither the second circuit nor the detection unit needs to contact the object, thus achieving non-contact temperature measurement. On the other hand, because the equivalent impedance of the first circuit changes with the temperature of the object, and the equivalent impedance of the second circuit changes with the equivalent impedance of the first circuit, the impedance change is not constrained by the external environment. In actual measurements, the detection unit only needs to detect the peak voltage. Based on the peak voltage, the equivalent impedance of the second circuit, the equivalent impedance of the first circuit, and the temperature of the object under test can be calculated sequentially. Furthermore, the non-contact temperature detection device has a simple structure, eliminates the need for expensive components such as infrared probes, saves production costs, and is widely applicable.
[0017] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of this utility model, nor is it intended to limit the scope of this utility model. Other features of this utility model will become readily apparent from the following description. Attached Figure Description
[0018] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0019] Figure 1 This is a schematic diagram of the structure of a non-contact temperature detection device provided in an embodiment of this utility model;
[0020] Figure 2 This is a schematic diagram of another non-contact temperature detection device provided in this embodiment of the present invention. Detailed Implementation
[0021] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.
[0022] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this utility model are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the utility model described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.
[0023] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.
[0024] Furthermore, the terms "upper," "lower," "left," and "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.
[0025] Example 1
[0026] Figure 1 This is a schematic diagram of a non-contact temperature detection device provided in an embodiment of this utility model. The non-contact temperature detection device can be applied to various scenarios requiring temperature measurement. For example... Figure 1 As shown, the non-contact temperature detection device includes: a sensing unit 100 and a detection unit 200.
[0027] The sensing unit 100 includes a first circuit 101 and a second circuit 102. The first circuit 101 is disposed inside or on the surface of the object under test, and is used to sense temperature changes in the object under test. Specifically, the equivalent impedance of the first circuit 101 changes with the temperature of the object under test.
[0028] The second circuit 102 is coupled to the first circuit 101, and the equivalent impedance of the second circuit 102 changes with the equivalent impedance of the first circuit 101.
[0029] In one embodiment, the equivalent impedance of the second circuit 102 is negatively correlated with the equivalent impedance of the first circuit 101. That is, the equivalent impedance of the second circuit 102 decreases as the equivalent impedance of the first circuit 101 increases; and the equivalent impedance of the second circuit 102 increases as the equivalent impedance of the first circuit 101 decreases.
[0030] It should be understood that the non-contact temperature detection device disclosed in this utility model refers to the fact that there is no connection between the first circuit 101 and the second circuit 102, and they do not come into contact with each other, not that the first circuit 101 does not come into contact with the object to be measured. Non-contact signal transmission can be achieved through the coupling of the first circuit 101 and the second circuit 102.
[0031] The detection unit 200 is electrically connected to the second circuit 102 and is used to sample from the second circuit 102 to obtain the peak voltage and calculate the equivalent impedance of the second circuit 102 based on the peak voltage, so as to determine the temperature of the object to be measured based on the equivalent impedance of the second circuit 102.
[0032] Specifically, the detection unit 200 can first calculate the equivalent impedance of the second circuit 102 based on the peak voltage, and then derive the equivalent impedance of the first circuit 101 based on the equivalent impedance of the second circuit 102. Thus, based on the mapping relationship between the equivalent impedance of the first circuit 101 and the temperature of the object to be measured, the temperature of the object to be measured can be determined.
[0033] In one embodiment, Figure 2 This is a schematic diagram of another non-contact temperature detection device provided in an embodiment of this utility model. Figure 2 As shown, the first circuit 101 includes a thermistor R1, a first capacitor C1, and a first electromagnetic coil L1 connected in parallel. Specifically, one end of the thermistor R1 is electrically connected to one end of the first capacitor C1, and the other end of the thermistor R1 is electrically connected to the other end of the first capacitor C1; one end of the thermistor R1 is electrically connected to one end of the first electromagnetic coil L1, and the other end of the thermistor R1 is electrically connected to the other end of the first electromagnetic coil L1.
[0034] The thermistor R1 is in direct contact with the object under test. The thermistor R1 is a temperature-sensitive semiconductor resistor whose resistance changes significantly with temperature, and this change is predictable. In this invention, the thermistor R1 can be either a negative temperature coefficient thermistor (NTC thermistor) or a positive temperature coefficient thermistor (PTC thermistor). A negative temperature coefficient thermistor's resistance decreases as the temperature of the object under test increases and increases as the temperature decreases. A positive temperature coefficient thermistor's resistance increases as the temperature of the object under test increases and decreases as the temperature decreases.
[0035] The advantages of the thermistor R1 lie in its low cost, miniaturization, and fast response, which can significantly reduce the production cost of non-contact temperature detection devices. Furthermore, the thermistor R1 is insensitive to lubricating grease, avoiding the influence of parameters such as the thickness and transparency of the lubricating grease on the infrared probe.
[0036] The first capacitor C1 and the first electromagnetic coil L1 are in a parallel resonant state. According to the characteristics of the parallel resonant circuit, the equivalent impedance of the first circuit 101 is equal to the resistance of the thermistor R1.
[0037] In one embodiment, reference continues Figure 2 The second circuit 102 includes a second electromagnetic coil L2, a second capacitor C2, a third capacitor C3, an inductor L3, and an inverter 103; wherein, the second electromagnetic coil L2 and the second capacitor C2 are connected in series and then connected in parallel with the third capacitor C3 and the inductor L3, and the inverter 103 is connected in series with the inductor L3.
[0038] One end of the second electromagnetic coil L2 is electrically connected to one end of the second capacitor C2, and the other end of the second capacitor C2 is electrically connected to one end of the third capacitor C3. The other end of the third capacitor C3 is electrically connected to the other end of the second electromagnetic coil L2. One end of the inductor L3 is electrically connected to one end of the third capacitor C3, and the other end of the inductor L3 is electrically connected to the other end of the third capacitor C3. The inverter 103 is connected in series between the other end of the inductor L3 and the other end of the second electromagnetic coil L2.
[0039] Inverter 103 receives an external DC signal and converts it into an AC carrier signal. The second electromagnetic coil L2 is coupled to the first electromagnetic coil L1. This coupling also powers the first circuit 101, avoiding the need for power supply / battery replacement in active circuits and giving the non-contact temperature detection device an extended operating range.
[0040] The second electromagnetic coil L2 and the second capacitor C2 are in a series resonant state, while the third capacitor C3 and the inductor L3 are in a parallel resonant state. According to the characteristics of a series resonant circuit, the equivalent impedance of the second electromagnetic coil L2 and the second capacitor C2 is 0. This greatly reduces the calculation complexity of the equivalent impedance of the second circuit 102.
[0041] In one embodiment, the carrier frequency of the AC carrier signal is f; the resonant frequencies of the first capacitor C1 and the first electromagnetic coil L1, the second electromagnetic coil L2 and the second capacitor C2, and the third capacitor C3 and the inductor L3 are all f.
[0042] Since the carrier frequency of the AC carrier signal is f and the maximum voltage is U, when the AC carrier signal passes through the resonant network of the third capacitor C3 and the inductor L3, the resonant frequency of the third capacitor C3 and the inductor L3 is f. It can be known that the current flowing through the second electromagnetic coil L2 is I = U / (2πf*L3), and this current does not change with other circuit parameters.
[0043] According to the impedance reflection formula, the equivalent impedance Z of the second circuit is... ref The equivalent impedance R1 of the first circuit satisfies the following relationship: Z ref =(2πf*M) 2 / R1; Since the current I flowing through the second electromagnetic coil L2 does not change with other circuit parameters, the peak voltage V dect The equivalent impedance Z of the second circuit ref Satisfying the following relationship: V dect =I*Z ref Where L3 is the inductance value of the inductor; M is the mutual inductance value between the first electromagnetic coil and the second electromagnetic coil.
[0044] In one embodiment, the mutual inductance M between the first electromagnetic coil and the second electromagnetic coil is determined based on the relative position of the first electromagnetic coil and the second electromagnetic coil (such as relative distance, eccentricity, etc.), the geometric parameters of the first electromagnetic coil and the second electromagnetic coil (such as the number of coil turns, size, etc.), and the permeability of the surrounding medium.
[0045] In one embodiment, the detection unit 200 includes an envelope detection circuit.
[0046] The envelope detection circuit can be any of the following: diode envelope detection circuit, precision rectifier envelope detection circuit, peak envelope detection circuit, or logarithmic amplifier envelope detection circuit.
[0047] The working principle of the non-contact temperature detection device is as follows: the resistance of the thermistor R1 changes with the temperature of the object being measured, causing a change in the equivalent impedance of the first circuit 101, which in turn changes the equivalent impedance of the second circuit 102. This ultimately results in a change in the peak voltage detected by the detection unit 200. The detection unit 200 can calculate the equivalent impedance of the second circuit 102 based on the peak voltage, and then derive the equivalent impedance of the first circuit 101 based on the equivalent impedance of the second circuit 102. Therefore, based on the mapping relationship between the equivalent impedance of the first circuit 101 and the temperature of the object being measured, the temperature of the object can be determined.
[0048] The technical solution of this utility model embodiment involves designing the structure of a non-contact temperature detection device, which includes a sensing unit and a detection unit. The sensing unit includes a first circuit and a second circuit. The first circuit is disposed inside or on the surface of the object to be measured, and its equivalent impedance changes with the temperature of the object. The second circuit is coupled to the first circuit, and its equivalent impedance changes with the equivalent impedance of the first circuit. The detection unit is electrically connected to the second circuit and is used to detect peak voltage and calculate the equivalent impedance of the second circuit based on the peak voltage, thereby determining the temperature of the object to be measured based on the equivalent impedance of the second circuit. On one hand, because the second circuit is coupled to the first circuit and the detection unit is electrically connected to the second circuit, only the first circuit needs to be disposed inside or on the surface of the object to be measured; neither the second circuit nor the detection unit needs to contact the object, thus achieving non-contact temperature measurement. On the other hand, because the equivalent impedance of the first circuit changes with the temperature of the object, and the equivalent impedance of the second circuit changes with the equivalent impedance of the first circuit, the impedance change is not constrained by the external environment. In actual measurements, the detection unit only needs to detect the peak voltage. Based on the peak voltage, the equivalent impedance of the second circuit, the equivalent impedance of the first circuit, and the temperature of the object under test can be calculated sequentially. Furthermore, the non-contact temperature detection device has a simple structure, eliminates the need for expensive components such as infrared probes, saves production costs, and is widely applicable.
[0049] Example 2
[0050] This utility model embodiment also provides a motor, including the non-contact temperature detection device of any of the above embodiments.
[0051] In one embodiment, the object to be tested can be the rotor of a motor, and the second circuit and detection unit of the non-contact temperature detection device are located on the stator side of the motor, but are not limited thereto.
[0052] Optionally, the motor can be installed in any device that requires a motor. For example, in an electric vehicle, the electric vehicle can be an electric two-wheeler (such as an electric bicycle) or an electric tricycle.
[0053] The specific embodiments described above do not constitute a limitation on the scope of protection of this utility model. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the scope of protection of this utility model.
Claims
1. A non-contact temperature detection device, characterized in that, include: Sensing unit and detection unit; wherein, The sensing unit includes a first circuit and a second circuit; the first circuit is disposed inside or on the surface of the object to be measured, and the equivalent impedance of the first circuit changes with the temperature of the object to be measured; the second circuit is coupled to the first circuit, and the equivalent impedance of the second circuit changes with the equivalent impedance of the first circuit. The detection unit is electrically connected to the second circuit and is used to detect the peak voltage and calculate the equivalent impedance of the second circuit based on the peak voltage, so as to determine the temperature of the object under test based on the equivalent impedance of the second circuit.
2. The non-contact temperature detection device according to claim 1, characterized in that, The first circuit includes a thermistor, a first capacitor, and a first electromagnetic coil connected in parallel; The thermistor is in direct contact with the object under test; The first capacitor and the first electromagnetic coil are in a parallel resonant state.
3. The non-contact temperature detection device according to claim 2, characterized in that, The second circuit includes a second electromagnetic coil, a second capacitor, a third capacitor, an inductor, and an inverter; wherein the second electromagnetic coil and the second capacitor are connected in series and then connected in parallel with the third capacitor and the inductor, and the inverter is connected in series with the inductor; The inverter is used to convert external DC signals into AC carrier signals; The second electromagnetic coil is coupled to the first electromagnetic coil; The second electromagnetic coil and the second capacitor are in series resonant state, and the third capacitor and the inductor are in parallel resonant state.
4. The non-contact temperature detection device according to claim 3, characterized in that, The carrier frequency of the AC carrier signal is f; The resonant frequencies of the first capacitor and the first electromagnetic coil, the second electromagnetic coil and the second capacitor, and the third capacitor and the inductor are all f.
5. The non-contact temperature detection device according to claim 4, characterized in that, The peak voltage V dect The equivalent impedance Z of the second circuit ref Satisfying the following relationship: V dect =I*Z ref ; The equivalent impedance Z of the second circuit ref The equivalent impedance R1 of the first circuit satisfies the following relationship: Z ref =(2πf*M) 2 / R1; Where I = U / (2πf*L3), U is the maximum voltage of the AC carrier signal, L3 is the inductance value of the inductor, and M is the mutual inductance value between the first electromagnetic coil and the second electromagnetic coil.
6. The non-contact temperature detection device according to claim 5, characterized in that, The mutual inductance M between the first electromagnetic coil and the second electromagnetic coil is determined based on their relative positions, their geometric parameters, and the permeability of the surrounding medium.
7. The non-contact temperature detection device according to claim 1, characterized in that, The detection unit includes an envelope detection circuit.
8. The non-contact temperature detection device according to claim 7, characterized in that, The envelope detection circuit can be any one of the following: diode envelope detection circuit, precision rectifier envelope detection circuit, peak envelope detection circuit, or logarithmic amplifier envelope detection circuit.
9. An electric motor, characterized in that, Includes the non-contact temperature detection device as described in any one of claims 1-8.
10. The motor according to claim 9, characterized in that, The object to be tested is the rotor of the motor, and the second circuit and detection unit of the non-contact temperature detection device are located on the stator side of the motor.